(written from a Production point of view)
Gene Dynarski (13 September 1933 – 27 February 2020; age 86) was an actor, who appeared twice in Star Trek: The Original Series and once in Star Trek: The Next Generation. He started acting in 1965; his role as Ben Childress was among his first. He has worked steadily in small television and movie roles since then. He is one of the few actors to appear on Star Trek: The Original Series and later one of the spin-offs.
Dynarski filmed his scenes for "Mudd's Women" on Tuesday 7 June 1966 at Desilu Stage 9, and between Thursday 9 June 1966 and Monday 13 June 1966 at Stage 10. He filmed his scenes for "The Mark of Gideon" on Wednesday 30 October 1968 and Thursday 31 October 1968 at Stage 9 and Stage 10.
Dynarski acted in numerous film and television projects, most notably Steven Spielberg's 1971 debut thriller Duel, which was written by Richard Matheson (based on his own short story) and featured Charles Seel and Carey Loftin, and the highly acclaimed 1976 drama, All the President's Men, which co-starred Stephen Collins, F. Murray Abraham, Richard Herd, Nicholas Coster, and Paul Lambert. In 1997 he made two appearances on Seinfeld (with Jason Alexander) as Izzy Mandelbaum, Jr.